1. Field of the Invention
This invention relates generally to the field of engine charge air intake systems and, more particularly, to a system for collecting condensation present in cooled charge air from a turbocharger prior to introduction into the engine intake manifold and mixing with recirculated exhaust gas.
2. Description of the Related Art
Most turbocharged engines, particularly heavy duty diesel engines, use charge air cooling to increase the brake specific horsepower output for the given engine displacement. Typically, a charge air cooler is used to cool the charge air from the turbocharger compressor. As the charge air is cooled, free water is formed from the condensed ambient humidity. With the introduction of Exhaust Gas Recirculation (EGR) systems onto heavy duty diesel engines, excessive condensation entrained within the engine""s charge air system has become a concern. The EGR system coats the intake manifold and other portions of the engine with products of combustion which, when dissolved in the normal condensation from the charge air system, results in an acid solution. It has been demonstrated that this acid solution has a negative impact on the durability of the engine.
EGR systems utilize an EGR mixer in the charge air system to assist the flow of EGR into the engine""s intake system. In certain EGR systems a Venturi in the charge air system is use to assist the flow of EGR into the engine""s intake system.
It is therefore desirable to extract the condensation from the charge air system prior to mixing with recirculated exhaust gas to prevent or minimize the formation of acid solutions which can damage the engine.
It is also desirable that a condensation separator be integrated into the charge air Venturi design, for engines employing that type of device, such that a compact system of water extraction as well as Venturi assisted EGR flow is achieved.
The present invention provides a charge air condensation separation system for a turbocharged engine. Especially suited for engines employing EGR, the system includes a turbocharger having a compressor providing charge air with a charge air cooler connected to the compressor to cool the charge air. A charge air delivery duct is connected to an outlet of the charge air cooler and a torroidal trap having an inlet annularly disposed in the charge air delivery duct is provided with an integral sump for collecting the condensate. The system is completed with a drain line for removing condensate from the sump for expulsion to the atmosphere. A pump or other device for overcoming pressure differential in the drain line is employed in certain embodiments.